Bernie Ecclestone has warned organisers of the Australian Grand Prix that their event is currently the "least viable" on the calendar.

Speculation over the future of the race has been rife for several years, with concerns about the cost of setting the race up each year and vocal opposition from certain members of the Victorian state parliament. Last year Ecclestone gave local fans hope when he said "Australia is just as important to us as Monaco and has been for an awful long time," but he now appears to have changed his mind.

"We have a contract which we will respect - so up until 2015 we are in good shape," Ecclestone told The Age on Wednesday. "After then, we really don't know. If we were to have a divorce from our friends in Melbourne we would probably be walking away from Australia. Because I can't see how Adelaide could make it happen, or anywhere else, if Melbourne can't. The race itself, from our point of view, is probably the least viable of all the races we have."

He said the grand prix would have to continue to make financial sense to Formula One's owners with potential venues emerging away from Formula One's traditional destinations.

"We have other races ready to take the place of Australia - which we don't want to happen. But it would be wrong of me to have to report to our board, 'Terribly sorry about this but we have to walk away from wherever to retain Australia'.''